I have a service dog too. And he has helped my immensely with my social phobia. Because of him I get out several times a day to walk him and get to chat with folks in the neighborhood.
Helps me with my depression too. I know others who have psychiatric service dogs too.
My service dog and a friends service dog aren't trained to be service dogs. They are just obediance trained. We got notes from are doctors stating that they are service dogs. My friend and I also carry cards saying that they are service dogs which can help. The card also has a phone# that they can call telling them the law in regards to service dogs. The phone # is of an agency that is part of the U.S. Department of Justice.